Endoscope equipped with a film cassette

ABSTRACT

An endoscope has within the forward end section of a sheath a cassette loaded with a roll of film on which a body cavity of a human being is photographed. One end of a film take-up shaft on the cassette outwardly extends from a housing of the cassette and a pulley is fixed on the outer periphery of the extending end portion of the film take-up shaft. A string is wound around the pulley. The string is inserted through a single passage in the sheath and when the string is pulled by an operator at a control section the film is wound.

BACKGROUND OF THE INVENTION

This invention relates to an endoscope having a flexible sheath and inparticular an endoscope equipped with a film cassette disposed withinthe forward end section of a sheath insertible into a body cavity of ahuman being and having a roll of film on which any affected portion ofthe body cavity can be photographed.

A conventional endoscope such as a gastroscope, includes a photographingdevice such as a patrone, cartridge or cassette (hereinafter referred tomerely as a cassette) within the forward end portion of a sheath, and abody cavity of a human being is photographed through a photographingwindow provided at the forward end portion of the sheath. A film issequentially fed frame by frame, during the photographing, into thesheath by a manual operation at a control section of the endoscope. Uponcompletion of photographing, the sheath is withdrawn from the bodycavity of a human being and a cap member is removed from the forward endsection of the sheath and an exposed film is taken out, together withthe cassette, from the forward end section of the sheath. Therefore,there is a fear that the exposed film will be impaired due to theexposure of a daylight. It is required that the exposed film be takenout at a dark room.

Furthermore, since the exposed film is sequentially withdrawn from thecassette into the sheath, a restriction is imposed on the inner diameteror size of the sheath. That is, the inner diameter of the sheath can notbe made too small due to the width of the film. In view of a currentrequirement that the inner dimension of a sheath be made minimal toalleviate pains of a patient, a problem is posed here. If the width of afilm is made narrower instead of increasing the width of the sheath, anobserved area corresponding to any affected portion of the inner cavityof a patient is narrowed, making it impossible for the observer toclearly and fully observe the affected portion of the inner cavity. Asthe width of the film is made narrower, there is a fear that the filmwill be torn apart. For this reason, the sheath can not be bent to agreater extent and in this sense a restriction is made to theflexibility of the sheath.

SUMMARY OF THE INVENTION

It is accordingly the object of this invention to provide an endoscopeloaded with a cassette disposed within the forward end section of asheath and having a roll of film, in which the film can be readily takenup in a simple arrangement.

In a preferred embodiment of this invention one end of a film take-upshaft externally extends from a cassette and a pulley is fixed on theextending end of the film take-up shaft. A string has one end woundaround the pulley and the other end inserted through a single passagewhich is provided in the longitudinal direction of a flexible sheath.When the string is pulled by a manual operation at a control section ofthe endoscope, the pulley and thus the film take-up shaft are rotated asa unit to permit a film to be wound in an intermittent manner. In sucharrangement, the single passage has only to be provided in thelongitudinal direction of the sheath and the film per se is not passedthrough the single passage of the sheath. Therefore, a fine string canbe used for a corresponding small diameter passage and in consequence itis not necessary that the outer diameter of the sheath be increased.Furthermore, the cassette can be taken out in broad daylight after aphotograph is taken, and it is not necessary that an exposed film betaken out at a dark room.

In another embodiment of this invention, a rib means is provided inclose proximity to an outer periphery of a pulley fixed on the endportion of a film take-up shaft which externally extends from acassette. The rib means is cut out to a section from which a string isdelivered. When the string is pulled for photographing, the rib meansprevents the string from being disengaged from the pulley.

In a further embodiment, a loop of variable size is provided on thedelivery end of a string and a hook provided on one end of an operatingwire extending from a control section is releasably anchored to the loopof the string. When the string is pulled by the operating wire with thestring anchored to the wire, the loop becomes smaller in size with theresult that the loop is tied to the hook of the wire. When, therefore,the string is pulled through a single passage of a sheath, there is nofear that the loop will be disengaged from the hook. Furthermore, thestring can be smoothly pulled with the loop tightened on the hook of thewire and in so doing the loop of the string undergoes no appreciablefrictional contact with the inner wall of the small diameter singlepassage.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 shows a general view, partially broken away, showing a filmcassette equipped endoscope according to one embodiment of thisinvention;

FIG. 2 shows an enlarged longitudinal view as taken in a directionvertical to a film take-up shaft on the film cassette in FIG. 1;

FIG. 3 is a bottom view, partly broken away, showing the film cassettein FIG. 2;

FIG. 4 is a partially enlarged view particularly showing only a forwardportion of a film cassette equipped endoscope according to anotherembodiment of this invention;

FIG. 5 is a partially cross-sectional view, as taken along line 5--5,showing the film cassette in FIG. 4;

FIG. 6 is a top view, partially broken away, showing the film cassettein FIG. 5;

FIG. 7 is an enlarged, cross-sectional view, as taken along line 7--7,showing the film cassette in FIG. 4; and

FIG. 8 is a modified form of a connecting means between a string woundaround a pulley on the film cassette and an operating wire providedwithin an endoscope body.

DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 1 shows an endoscope according to this invention. The endoscope hasa lengthy flexible sheath 10 and a control section 11 provided on thebase end of the flexible sheath 10. The endoscope is, for example, agastrofiberscope and the flexible sheath 10 is adapted to be inserted bythe operation of the control section 11 into a body cavity (not shown)of a human being. The sheath 10 includes a flexible outer tube 12extending substantially over the entire length thereof and only aforward end section 10a of the flexible sheath 10 comprises acylindrical metal member 13 and a metallic cap member 14 threadablyfitted over the free end of the member 13 and having a round outersurface. An image guide fiber bundle 15 and light guide fiber bundle 16are disposed, in the longitudinal direction of the sheath 10, within thesheath 10 and optically connected to windows 17 and 18 in thecylindrical metal member 13. The bundle 15 sends an image correspondingto a body cavity (not shown) under observation of a human being to thecontrol section 11 through the window 17 and the bundle 16 sends a lightfrom the control section 11 through the window 18 to the body cavityunder observation of the human being. The construction of the bundles 15and 16 and their operation at the control section 11 is known in the artand further explanation is therefore omitted.

Within the forward end section 10a of the sheath 10 is disposed a filmcassette or cartridge 20 (hereinafter referred to merely as a cassette)loaded with a rolled film 19. The cassette 20 is positioned, by cassettepositioning frame members 21 and 22, within a cassette chamber 23 in theforward end section 10a of the sheath 10 and securely held by a leafspring 24 and coil spring 25 in a set position. The positioning framemembers 21 is fixed to the inner surface of the member 13 and thepositioning frame member 22 is fixed to the front end surface of themember 13. The leaf spring 24 has one end fixed to the inner surface ofthe member 13 and the coil spring 25 has one end fixed to the innersurface of the cap member 14. A photographing window 26 is provided inthe cylindrical metal member 13 and a photographing lens 27 is disposedin proximity to the photographing window 26.

As shown in full in FIGS. 2 and 3 the cassette 20 has a housing means 30comprising a pair of side housings 30a, 30b and a main housing 30c. Withthe cassette 20 in a state shown in FIG. 1 an exposure window 31optically connected to the optical system 26, 27 is opened in thehousing means 30 and thus the main housing 30c. A roll shaft 33 isdisposed in a film roll chamber 32 which is located at one side of thehousing means 30 (to the left of the cassette 20 in FIG. 2), and a film19 is rolled around the roll shaft 33 to provide a film roll body 19a. Afilm take-up shaft 35 is disposed in a chamber 34 which is located atthe other side (to the right of the cassette 20) of the housing means 30with an exposure window 31 between the chambers 32 and 34. The film 19is supplied in a direction indicated by an arrow A in FIG. 2, i.e., fromthe roll shaft 33 through an exposure window 31 to the take-up shaft 35in the chamber 34 in the cassette 20. The shafts 33 and 35 are rotatablysupported on the side housings 30a and 30b. Light shielding filters 36and 37 prevent an entry into the chambers 32 and 34 of a light which isincident from the exposure window 31 into the cassette 20. The film 19is sent through the light shielding filters 36 and 37.

As shown in FIG. 3 one end of the take-up shaft 35 has a shaft means 40integral therewith. The shaft means 40 outwardly extends from the sidehousing 30a and a pulley 41 is fixed to the shaft means 40.Alternatively the shaft means 40 may be formed separately from thetake-up shaft 35 and it can be rotated as a unit with the take-up shaft35. The pulley 41 may be formed integral with the shaft means 40.

One end of a string 42 is wound around a pulley 41 and the string 42 ismade of a suitable flexible material free from expansion andcontraction. The end portion of the string 42 is doubled back uponitself with the free end thereof fixed as at 42b to provide a loop 42a.In consequence, the loop has a predetermined size. When the string 42 ispulled in a direction indicated by B in FIG. 3, the take-up shaft 35 isrotated through the pulley 41 and shaft means 40 to permit the film 19to be taken up in a direction of A in FIG. 2.

As shown in FIG. 1 a single passage 43 with a small inner diameter ofabout 1 mm is provided in the sheath 10 along the longitudinal directionof the sheath 10. For example, the passage 43 is provided by a slendertube. The passage 43 extends from the frame 21 to the control section 11and the string 42 is passed through the passage 43 as shown in FIG. 1.

A string pulling means, i.e., an operating wire 44 is provided in theendoscope and the string 42 can be pulled away from the shaft 35 byoperating the wire 44 at the control section 11. The operating wire 44has a hook 44a at the forward end and the hook 44a is removably anchoredto the loop 42a of the string 42. The wire 44 is made of a suitable,relatively pliable material free from expansion and contraction. Thebase end of the wire 44 is fixed to a take-up drum 45 in the controlsection 11 and the drum 45 is connected to a rotation operating knob 46which projects outside of the control section 11. When the knob 46 isrotated, the wire 44 is taken up on the drum 45. It will be understoodthat, when the knob 46 is rotated in one direction, the film 19 in thecassette 20 is sequentially taken up in a direction indicated by thearrow A in FIG. 2.

When an intended photographing is completed through the cassette film19, the sheath 10 is withdrawn from the body cavity of the human beingand the cap member 14 is unscrewed and the cassette 20 is removed fromthe cassette chamber 23. In this case, the string 42 and operating wire44 are drawn out together. It will be sufficient if the wire 44 is drawnout to a position where the hook 44a anchored to the string 42 appearsoutside. The hook 44a of the wire 44 is removed from the loop 42a of thestring 42 and the string 42 is again suitably wound on the pulley 41.The rolled film 19 can be taken out from the film cassette 20 byremoving the side housing 30b from the main housing 30c.

FIGS. 4 to 7 shows an endoscope according to a second embodiment of thisinvention. In this embodiment the structure of a sheath and controlsection is substantially similar to that of the first embodiment exceptfor the interior arrangement of a forward end section of a sheath, andtherefore only a different part of the sheath is shown in these Figures.The second embodiment is different from the first embodiment in thestructure per se of a film cassette. Like reference numerals areemployed to designate like parts or elements corresponding to thoseshown in the first embodiment, with an addition of different referencenumerals to different parts or elements.

In FIG. 4 a film cassette 50 is received in a cassette chamber 23 in theforward end section 10a of a flexible sheath 10. A means for positioningthe film cassette 50 within the cassette chamber 23, that is, framemembers 21 and 22, leaf spring 24 and coil spring 25 is substantiallysimilar to that of the first embodiment, but the shape of the framemembers 21 and 22 and the mounting of the leaf spring 24 on acylindrical metal member 13 are somewhat different from those of thefirst embodiment.

A cassette 50 has a housing means 51 consisting of two side housings 51aand 51b removably fitted one on the other. An enlarged chamber 52 isprovided at one side of the housing means 51 (to the left in FIG. 4) anda flattened chamber 53 is provided at the other side of the housingmeans 51 (to the right in FIG. 4). A film roll body 54a of a rolled film54 and a film take-up shaft 55 are disposed in the enlarged chamber 52and the film take-up shaft 55 is rotatably supported on the sidehousings 51a and 51b. An exposure window 56 is formed on the sidehousing 51b of the housing means 51. As shown in FIG. 7 a partitionsection 51c is integrally projected from the side housing 51a and fittedinto the housing 51b and as shown in FIG. 5 a film guide shaft 57 isintegrally projected from the housing 51a. A collar 58 is fitted overthe film guide shaft 57. It will be understood that the film guide shaft57 can be formed independently of the housing 51a.

The film 54 is delivered from the film roll body 54a, down through thepartition section 51c, to the film guide shaft 57 where it is U-turnedand fed in a direction of an arrow A in FIG. 4 toward a take-up shaft55. That is, the U-turned film is fed up through the partition section51c, while passing through an exposure window 56, to the take-up shaft55. Unlike the first embodiment, no support shaft is provided for thefilm roll body 54a. Even in the absence of such support shaft noinconvenience is involved in the film delivery. Light shielding filters59 and 60 perform the same function as those shown in the firstembodiment.

With a cassette 50 equipped in a cassette chamber 23 the exposure window56 of the cassette 50 is optically connected to an optical system, i.e.,a photographing window 26 and photographing lens 27.

As shown in FIGS. 5 and 6 one end of the take-up shaft 55 externallyextends from the side housing 51a to provide a shaft means 61 on which apulley 62 is mounted. A string 63 is wound around the pulley 62. Whenthe string 63 is delivered in a direction of an arrow B, the take-upshaft 55 is rotated through the pulley 62 and thus the shaft means 61.In this way, the film 54 is taken up as in the first embodiment. Inclose proximity to the outer periphery of the pulley 62 an annular rib64 is provided integral with the side housing 51a. The annular rib 64 isformed concentric with the rotation axis of the pulley 62. The annularrib 64 is partially cut to leave an arcuate section, and the cut-outsection 65 of the rib 64 permits the string 63 to be deliveredtherefrom. The presence of the rib 64 prevents the string 63 from beingunwarrantedly disengaged from the pulley 62. The rib 64 can be formedseparately from the housing 51a and in this case it is fitted on thehousing 51 a. The cassette 50 in the second embodiment has the followingadvantages. The length of the cassette 50 can be shortened, since thefilm roll body 54a and take-up shaft 55 are disposed in the enlargedchamber 52. To explain more in detail, a distance between the film rollbody 54a and the take-up shaft 55 can be minimized, since the diameterof the film roll body 54a is decreased with a delivery of the film 54from the film roll body 54a and since the diameter of a roll of filmwound around the take-up shaft 55 is correspondingly increased. Asmentioned above, the extent to which the string 63 is unwarrantedlydisengaged from the pulley 62 can be reduced to a minimum. This avoidsany inconvenience when the sheath is inserted into the body cavity of apatient and a photograph is taken during the observation of the bodycavity.

FIG. 8 is a modified form of an anchoring means between a string and anoperating wire. In this Figure, a string 71 is wound around a pulley 70as in the case of the first and second embodiments and it corresponds tothe strings 42 and 63 in the first and second embodiments, respectively.An operating wire 72 in this embodiment corresponds to the operatingwire 44 shown in the first embodiment. A loop 71a is formed, as adelivery end, in the free end portion of the string 71 and a small loop71b is also formed at the fixed portion of the loop 71a so that, whenthe small loop 71b is slidably moved along the string 71, the size ofthe loop 71a can be varied. A grip portion 71c extends from a knot ofthe small loop 71b. A hook 72a is formed, as in the first embodiment, atthe free end portion of a wire 72. The hook 72a of the wire 72 isanchored to the variable loop 71a.

Such anchoring means has the following advantages. When the wire 72 ispulled in a direction of an arrow B, the size of the loop 71a becomessmaller and smaller, since the small loop 71b is slidably moved towardthe hook 72a of the wire 72. As a result, the hook 72a and the loop 71aare closely tied together.

The single passage of the sheath has a small diameter of about 1 mm andthe loop of the string and hook of the operating wire is correspondinglysmall in size and there is a fear that the hook will be disengaged fromthe loop of the string. Since according to this invention the size ofthe loop can be varied, the loop is positively tied to the hook duringthe pulley operation. When the loop 71a is desired to be released fromthe hook 72a, the grip portion 71c of the string 71 is pulled away fromthe hook 72a and it will be easily released from the hook 72a, since thesize of the loop 71a become larger. Furthermore, the string can bepulled with a minimum frictional contact with the inner wall surface ofthe passage of the sheath, since the loop 71a of string 71 is compactlytied on the hook 72a of the wire 72.

What is claimed is:
 1. An endoscope having a sheath; a control sectiondisposed at the base of the sheath; said a film cassette disposed withinthe forward end section of the sheath said cassette having a housingmeans with an exposure window, a film received within said cassettehousing means and a film take-up shaft rotatably supported in saidcassette housing means, said shaft extending from the cassette housingmeans in a manner to be integral with the film take-up shaft; a pulleymeans fixed integral with said shaft means; a string whose one end iswound around the pulley means; a single passage provided in thelongitudinal direction of the sheath to permit a delivery end of saidstring to be passed through the single passage; and a string pullingmeans adapted to rotate said pulley means by pulling said string at saidcontrol section to permit said film to be wound around said film take-upshaft.
 2. The endoscope according to claim 1, in which said cassettehousing means has a rib means provided in close proximity to the outerperiphery of said pulley means and having at least cut out section fromwhich said string is delivered, the remaining portion of said ribpreventing said string from being disengaged from said pulley means. 3.The endoscope according to claim 2, in which said rib means is integralwith said housing means.
 4. The endoscope according to claim 1, in whichsaid string pulling means includes a wire extending from said controlsection into said single passage, one end of said wire being releasablyengaged with a delivery end of said string through a loop-hookconnection.
 5. The endoscope according to claim 4, in which a loop whosesize can be varied is provided at said delivery end of said string and ahook is formed at said one end of said wire so as to be anchored to saidloop of said string.